1. Field of the Invention
The present invention relates generally to the fields of molecular biology and vaccinology. More specifically, the present invention relates to a non-antibiotic system for selection of recombinant mycobacterium.
2. Description of the Related Art
Mycobacterium bovis bacille Calmette-Guerin (BCG) is the most extensively utilized attenuated live vaccine in the world today. Recent advances in mycobacterium vectors hold great promise for the development of effective and inexpensive recombinant-based vaccines. However, the use of antibiotic resistance genes for the selection of recombinant mycobacterium in preparation of the vectors remains problematic. It is inadvisable to administer a vaccine containing an antibiotic resistance gene if it can be avoided.
Dengue is caused by four serologically related viruses known as dengue types 1, 2, 3 and 4, which are found in most tropical parts of the world (including the Caribbean and Mexico) infecting approximately 20 million annually with a mortality rate of 5%. Dengue is an emerging disease that is spreading through the Americas and is likely to be increasingly introduced into Texas from Mexico. There are no vaccines currently available to prevent dengue.
The prior art is deficient in the lack of an effective non-antibiotic system for selection of recombinant mycobacteria such as Mycobaterium bovis BCG, mycobacterium smegmatis or other mycobacteria that may have potential as vaccines. The present invention fulfills this longstanding need and desire in the art.